Applicants copending U.S. application Ser. Nos. 882,239 and 934,950, filed respectively on July 3, 1986 and Nov. 26, 1986 and here incorporated by reference, are directed to calligraphic writing systems of the type including an x-y plotter, a writing pen mounted for movement relative to the plotter, and a digital computer that controls the movement of the pen relative to the plotter. Such systems are currently being sold by Inscribe, Inc. of Cambridge, Mass., and are used for automatically writing such things as wedding invitations, envelopes, and table place cards, and for filling in blanks on preprinted diplomas and similar certificates.
In prior art systems, only a single card, envelope or sheet of paper was placed on the plotter writing bed at any one time. The correct location of the item to be written on was indicated by alignment marks at the bottom and along the left side of the writing bed. Precise alignment of the pen relative to the item to be written could be difficult to achieve; although the relative locations of the plotter bed and pen support structure remained the same, the exact location of the pen point relative to the support would vary somewhat depending on the particular pen, pen orientation, and pen point size.